I would treat tryouts like its the first day of practice. I would go straight into Layer 1 and show them how to get into it from transition and eventually scrimmage with the expectation that they do it. It will tell you who is TEACHABLE and who can shoot lay-ups, pass, catch on the move, and run the floor.
It will also allow you to see which kids can keep up with all of this on DEFENSE.
If a kid can’t do these basics, or rather, WON’T do these basics, I would not want him/her on my team regardless of their skills.